Charlie's death was confirmed by North Wales Fire and Rescue. He had been in a critical condition in hospital.

A man, 45, and a woman, 42, have been arrested on suspicion of murder.

North Wales Police confirmed those being questioned had been living in the ground floor flat below.

'Heartbreaking incident'

The force said Charlie died at Alder Hey Children's Hospital in Liverpool surrounded by his family.

Image caption
Flowers were left outside the property

His father and Ms Shiers' partner Liam Timbrell, 23, is in a "critical but stable" condition, said police.

The family made a statement thanking the community of Prestatyn for their flowers, cards and messages of condolences.

"A special thanks from all the family goes to those individuals who made every effort on this tragic night to help and assist with the rescue of Lee-Anna, Liam, Charlie, Skye and Bailey and those who offered their support to the fire service and police," said the family.

"Thanks also go to all the hospital staff who have assisted in the care and treatment of those concerned in this heartbreaking incident."

Det Supt Jon Chapman said: "My sincere condolences go out to the family at this tragic time.

"We will continue to work closely with North Wales Fire and Rescue Service to determine what exactly happened and to ensure a through and meticulous investigation into this incident."

Neighbours had made "valiant" attempts to save the children from the first floor flat but were beaten back by flames, say firefighters.

Fire crews wearing breathing apparatus went into the property at Maes Y Groes at about 22:00 BST on Friday.